Embodiments described herein relate to a packaging structure for OLED device and a display apparatus.
Organic light-emitting diode (referred to as OLED) devices are widely used in the display industry since they have such advantages as solid-state structure, high brightness, full view angle, rapid response speed and capability of flexible display, etc. However, the water, oxygen and other ingredients in the air have a great influence on the life of the OLED device. Thus, in order to increase the service life of an OLED device, it is usually necessary to package the OLED device by using a packaging structure to isolate the OLED device from water, oxygen and other ingredients in the air.
In the prior art, a packaging structure for an OLED device comprises a plurality of films coated on the outer side of the OLED device which comprise alternately stacked inorganic layers and organic layers. Among the plurality of films, both the film in contact with the OLED device and the film farthest from the OLED device are inorganic layers. An inorganic layer is usually formed of SiNx (silicon nitride) material by using chemical vapor deposition (referred to as CVD). An organic layer is usually formed of organic material by using ink-jet printing process.
However, due to the large difference in wettability between the SiNx material and the organic material, resulting in large contact angle between the SiNx material and the organic material, it is difficult for the organic layer formed of the organic material to sufficiently spread on the inorganic layer formed of the SiNx material. Therefore, it is easy to form defects such as small holes in the organic layer, and the packaging structure cannot isolate the OLED device from water, oxygen and other ingredients in the air. As a result, the service life of the OLED device will be decreased.
Methods proposed in the prior art for reducing the defects such as small holes in the organic layer includes replacing the organic material for forming the organic layer, using a longer leveling time after the ink-jet printing process, or forming the organic layer after treating the surface of the inorganic layer by using plasma or ultra-violet ozone (referred to as UVO). However, such methods are expensive and would lengthen the unit production time of the production line. Accordingly, the applicability of above methods is poor.